Boston Mayor Thomas Menino has confirmed that the city is pushing for a multimillion-dollar tax break for Boston Properties as an incentive to build a new 45,000-square-foot Star Market adjacent to the TD Boston Garden.

The so-called Chapter 121A tax deal, which would provide $7.8 million in property-tax relief over 15 years for Boston Properties' proposed mixed-use development near the Garden, must be approved by the Boston Redevelopment Authority's board. The group is set to vote on the tax proposal as well as the development itself Dec. 19.

"For many years West End residents have asked for an accessible and convenient supermarket and today we can announce that this need will finally be met," said Menino in prepared remarks issued Thursday. “Bringing Star Market to this neighborhood is one of the key community benefits of the Boston Garden redevelopment plan and is considered of immeasurable value to residents of the West End, Bulfinch Triangle, and the North End."

According to the mayor's office, the existing undeveloped parcel generates $350,000 in annual property tax revenue for the city. Post development, the site is expected to annually generate around $2.1 million in new revenue to the city over a 15-year span.

As first reported by the BBJ Dec. 10, Boston Properties (NYSE: BXP) and theDelaware North Cos., owner of the TD Garden, recently notified the city that they had reached “a preliminary business agreement with a major supermarket operator and will announce the details publicly in the near future.” Sources at the time told the BBJ that the developers expected to sign a 45,000-square-foot lease for a Star Market within the next week. The supermarket would be housed in the lower level of the 1.7-million-square-foot mixed-use development to be built on a parking lot in front of the Garden. The entire development is expected to cost roughly $1 billion.

The city's efforts to assist Boston Properties in developing the West End parcel have raised hackles among neighborhood activists. In a letter to the mayor dated Dec. 11, members of the Boston Garden Impact Advisory Group accused the city of ignoring their protests over the height of the project's 45-story residential tower. The group, which was appointed by the city, also has complained about the development's traffic impacts and the appropriateness of the 121A tax agreement, given Boston Properties' financial strength and access to billions in capital.